Drill steel centralizer



June 6,1944. J. c. CURTIS 2,350,658

v DRILL STEEL CENTRALIZER Fi1ed July 21. 1941 WOM,

Patented June 6, 1944 vUNITED STATES PATENT OFFICE John c. Curtis, Claremont, N n., assignortpsuilivanMachinery Companyfa corporation of` Massachusetts Application July 21, 1941,'Vse'ria1No. 403,374

(o1. 255-'1)V 2 2 of Figi, and showingtnefguide members 26 claims.

Thisinvention relates to rock drills, and more particularly to a centralizer for a drill steel ac-v tuated by arock drill of theA hammer type. j 4 lIn drilling material such asrock it issometimes very diilicult to maintain' the'drillbit in axial alinement with the rock drill'. `Thisis particularly true when starting horizontal holes in uneven 'rock surfaces. Under such conditions the working end of a rapidly rotating drill steel Whips about, making it diilicult to start the hole correctly. The whipping action may be due partly to the exibility of the drill steel and partly to the clearances between the drill steel and the chuck mechanism of the rock drill into which the drill steel extends. As the chuck mechanism of zthe centralizer engaging thedrill'steel.

Y Fig. 3 'is' aview vsimilar to Fig. 2, but showingthe guide members in their released positions.

Fig. 4 is a plan view kwith parts broken away showingV thecentralizer and the'forward portion of ther-guideI shell.' f

' Fig. 5.7is an `enlarged sectional viewtaken on becomes worn the play between the parts increases and, in time, the action oan unsupported drill will interfere with the operation of the chuck rotation mechanism. If the drill steel is permittedv to drift out of alinement with the longitudinal axis of the drill, there will be produced a binding between the drill steel and its Work, thereby increasing theload on the drill .motor and causing excessive wear on the gaging sur'- faces of the cutting bit.

" It is an object of this invention to provide improved means for guiding the drill steel during a'portion of the drilling operation. Another objectofthe invention is to provide an improved drill steelcentralizer having improved means for positively locking guidejmembers in position for guiding the drill steel during the starting of the tlrill'hole.4 IStill another object isA to provide improved means for holding a drill steel in axial alinement with its actuating motor during a portion of the drilling operation andI automatically operative, when the hammer .motor reaches va predetermined point in its feed, to release the drijlyljsteel and moveout of the path of the motor. Another object is to provide an improved drill steel guide of the pivoted guide arm type'wherein the guide arms 'maybe individually swung about theirv pivots into guiding relation with-the drill steel, and having rindividual locking means. Other objects of the invention will, however, hereinafter more fully appear 'in .the course of the Fig. 7"isjafcross'sectional view taken on the line Tefloflgl." v` In the drawingto illustrate the invention, I have shown 'the front ends of a hammer drill and of v`a 'guide shell,` designated, respectively, I and 2. A drill steelll vis shown with its shank extending into the front head of the rock drill to receive the blows of a hammer piston (not shown),' and secured to the outer end of the drill steel is a cutting bit 6 which is shown here as being ofthe detachable type.

"lhe'rock drill `has the usual guide flanges 8 which are slidably receiv'edin guideways 9 in the shell 2 to enable the lrock drill to be moved and guidedA relative toA thework during drilling and retraction. 'Formed on the guideshell is a trunnion. portion I adapted to be clamped in a suitable'saddle of any Well known form of rock drill support.' `I Attached to the forward end ofthe guide shell is a drill steel centralizer, generally designated l2, constructed in accordance with the practice ofthe invention. The drill steel centralizer comprises a support member I4 herein shown as having a plate portion i5 extending acrossthe front end of the guide shell' and providing a bearing for the 'front end of a feed screw I6. Obviously theieedsfcrew 'I6 mayjbeotherwise supported. Projecting forwardly from the plate portion at its outer endsfare cylinder portions VI'I having bores i8 opening through their forward ends. Abutting the forward endsj ofI the cylinder portions Il are cylinder portions' 20 of a transverse member 2|, and formed :in the cylinder portions 2 0 are bores 22 in axial alinement'wi-th the bores I8 and opening into'thelatte'rl The members `I4 and 2| are iirmly secured to vthe front-endet the' guide shell by bolts' 24v` extending axially through the cylinder'-portionsjl'l and 20. 1 v

jl Ihe centralizer'includes guide members 25 for guiding theV drill` steel" duringv av portion of the drilling "operation, andthese guide members in# Y clude arms Ei having hub portions 21 which are received'in the boresIS-andn and are provided enough to permit the rock drill to pass between them, andV the dimensions of the openings longitudinally of the cylinder portions are somewhat greater than the corresponding dimensions ofthe arms 26 so `that the guide members may be moved Y bodily or transllationally relative to the cylinder portions for a reason to be shortly explained.

The surfaces at the outer edges of they openings o 30 act as abutments for limiting the Voutward swinging movement of the guide members.

Means are'provded for yieldably urging the guide members toward 4their outer angular positions and toward Vthe rear ends` of the cylinder bores I8. ThisV means comprises coiled springs 33 surrounding the portions of the. bolts 24 extendin-g Vthrough the bores 22 and having their forward ends fixed to the cylinder portions 20, and

their rear ends Vfixed to the hubs 21 of the guide members. Formed in the cylinder portions I1 at the rear ends of the (bores. IIV are recesses or grooves 3.5 for receiving projecting portions, such as tongues 36, on the rear ends of the hubs 21 when the guide members are in their drill-steelguiding positions. Due tothe force exerted by thefsprings 33,l the hubs 21 of the guide members are held rmly against the end walls of the bores I8, so that frictional contact between the hubs and the end walls of the 'bores aids i holding the guide members in their released positions. and when the, guide members are moved to positions for engaging the drill steel the tongues 36 move into the -grooves`35 and'effect a locking of the guide members in such positions. When the guide members are moved forwardly relative tothe cylinder portions I1 a suicient distance to remove the tongues 3.6 from the grooves 35, the springs 33 cause the members to swing outwardly about the bolts 24 until the arms 26 engage the outer edges of the openings 30. Formed on the rear faces of the arms 26 are projecting abutments 38 which are engaged by the front end of the rock drill for forcing the guide members forwardly relative, to the cylinder portions I1 and eiecting a release of the. tongues 35 from the grooves 3.6. Y

In the operation of the device, whenever it is desired to start a new drill holeV the guide members 25 may be swung into positions for engaging the sidesy of the drill steel, and the members are forced rearwardly by the springs 33 to effect a seating of the tongues 36in the grooves 35 for locking the guide members against any angular movement. The members remain` in their guiding positions duringI theV drilling of the hole until the Vfront end of the rock drill advances into contact withr the abutments 38 on the arms. 26 and forces the guide members bodily ahead to release the tongues from the grooves 35. Upon release bers are swung outwardlyjby the springs 33 sovthat the drill may continue its advancing, movement untilvtheA working implement. has penetrated the materialto., nie limit of its. extent. The guide arms may be placed indlvidually'in'guiding positions so that but a single guide arm may be used if that is all that is necessary in spotting a hole.

As a result of this invention it will be noted that the drill bit upon the drill steel will be held coaxial with the rock drill during the early portion of the drilling operation so as to prevent any departure of the drill from its desired course. It willv be further noted that the guide members are positively locked in their guiding positions until the drill has advanced a predetermined di'stance, at which time the guide members are released and automatically moved out of the path Vof the drill. It will be evident that by suitably interconnecting the guide members, as by gear sec-V tors or the like, locking and turning means applied to either member may control both members with; out departing from the spirit or the scope of my` invention.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1.v In ay drill'steel centralizer, in combination, a support, a pair of guide members pivotally mountedon said support on axes parallel to the longitudinal axis of a drill steel to be guided andv swingable relative to each other into guiding and non-guiding position, means carried by saidv guide members and engageable with said support for positively locking said guide members against outward swinging movement from their steel guiding position, and yielding means operatively connected to said guide members for always positively moving said guide members to their nonguiding position whenever said locking means is released; said locking means when in locking position locking said guide members inwardly in steel guiding position against the action of said yielding moving means.

2. In a drill steel centralizer, in combination, a support, a pair of guide members pivotally mounted on said support on spaced parallel axes extending longitudinally of a drill steel to be guided and swingable into guiding and non-guiding positions, means `for positively locking said guide members individually in their guiding position, and yielding means operatively connected' to said guide members for always individually positively moving said guide members to their non-guiding, position whenever said locking means is released.

3. In a drill steel centralizer, in combination, a support, a pair of guide members pivotally mounted on spaced parallel axes on said support for movement into guidingv and non-guiding positions, said' guide members being movable bodily relative to said supportV when in their guiding positions for effecting a locking of said guide members against pivotal movement, and yielding means for positively moving said guide members to their non-guiding positions when the latter are moved to positions for pivotal movement, said yielding means acting on said guide members of the tongues from the grooves., the guide mempositively to move the same in a lockingvdirection as well as in a direction towards non-guiding positions.

' L In a drill steel centralizer, in combination. a pair of guide members pivotally mounted on' axes extending parallel to a plane including the longitudinal' axis of the drill steel for movement into guiding and non-guiding positions, said guide members being movable jointly longitudinally of their pivotal axes when in their guiding positions for .eiecting a lockingof said guide members against pivotal movement, and yielding means vfor continuously urging said guide members about their pivotal axes toward their nonguiding positions. 5. In a drill steel centralizer,.in combination, a pair. of guide `members pivotally mountedfon axes extending `parallel'to a plane including the longitudinal axis vof the drill steel for movement into. guiding and non-guiding positions, said guide members being movable longitudinally of their pivotal axes when intheir guiding positions for effecting a locking `of said guide members against pivotal movement, and yielding means for continuously urging said guide members longitudinally of their pivotal axes toward positions in which said members are locked against pivotal movement, said lguide members being releasable automatically by concurrent longitudinal movement along their pivotal axes.

6. In a drill steel centralizer, in combination, a pair of guide members pivotally mounted on axes extending parallel to a plane including the longitudinal axis of the drill steelfor movement into guiding and non-guiding positions, said guide members being jointly movable longitudinally of their pivotal axes when in their guiding positions for effecting a locking of said guide members against pivotal movement, and yielding means for continuously urging said guide members longitudinally of their pivotal axes toward positions in, which said. members are locked against pivotal movement and angularly about their pivotal axes toward their non-guiding positions.

7. In a drillsteel centralizer, in combination, a support having a pair of bores extending parallel to and on opposite sides of a plane including the longitudinal axis of the drill steel, a pair of guide members having hub portions received within said bores and arm portions projecting outwardly perpendicular to the axes of said bores, said guide members rotatable about the axes of said `bores into guiding and non-guiding positions, means for positively locking said guide members against rotation when in their guiding positions, and means for continuously urging said guide members toward their non-guiding positions.

8. In a drill steel centralizer, inrcombination, a support lhaving a pair of bores extending parallel to and on opposite sides of a plane including the longitudinal axis of the drill steel, a pair of guide vmembers having hub portions received within said bores and arm portions projecting outwardly perpendicular tothe axes of said bores, said guide members rotatable about the axes of said bores into guiding and non-guiding positions, means for positively locking said guide members against rotation when intheir guiding positions including recesses in said support, projecting portions on said guide members receivable in said recesses, and means for continuously urging said guide members longitudinally of said bores toward said recesses.

I 9.v In a drill steel centralizer, in combination, a support havinga pair of bores extending parallel to and on opposite sides of a plane includ-` ing the longitudinal axis of the drill steel, a pair of, guide members having .hub portions received within'said bores land arm portions projecting outwardly perpendicular to the axes ofsaid bores,

said guide members rotatableiabout the'axes of saidbores into guiding and non-guiding positions, means for` positively locking said guideV members against rotation when in their guiding,v positions including recesses in said support open:l ing into one end of said bores, projectingportions on the. hub portions of said guide members receivable in saidrecesses when the guide members are in guiding positions, and yielding means for continuously urging said guide members ,longitudinally of said bores toward said recesses and angularlyA abouttheaes of said bores toward non-guiding positions. a ,t

v 10. .In a drill steel centralizer, in combination, a support having va pair of bores extending parallelto and on opposite sides of a` plane including thelongitudinal axis of the drill steel', a pair of guide members having hub portionsvreceived within said bores and arm portions projecting outwardly perpendicular to the axes ofsaidblores, said guide members rotatable about the axesof said bores intowguiding and non-guiding positions, means for positively lockingsaid guide` members against rotation when in their positions including recessesl in said supportopening into one end of said bores, projecting portions on the hub portions of said guide members receivable in said recesses when the guide members are in guiding positions, and coiled springs connected to said support and to the hub por-` tions of said guide members for continuously urging the latter longitudinally of said bores toward said recesses and angularly about the axes of said bores toward non-guiding positions.

1l. In a drill steel centralizer,'in combination, a support having bores therein, guide members having hub portions received within said bores and projecting arm portions' carrying steel engaging and guiding devices, said guide members pivotable on axes coincident with the axes of said bores between guiding and released positions, and means for Vcontrolling the positions of said guide members including means for releasably locking them in guiding position while in such position and for automatically moving them out of the way upon a predetermined vmovement while in such position.

l2. In a device of the character described, a drill steel guide member, means `for mounting said guide member for pivotal movement on an axis parallel to the longitudinal axis of a steel to be guided and for translatory movement longitudinally relative to the steel, means constantly tending to swing said guide member about its pivot out of steel guiding position, and means operative in a given position of said member and engaging said mounting means to hold said' guide member in guiding position, saidholding means rendered ineffective upon predetermined translatory movement of said guide member from said given position out of held engagement with said mounting means. Y Y 13. In a drill steel guide, a guide 'element engageable with a drill steel, mounting means* for said guide element providing for pivotal vand bodily movements thereof, locking means for holding said element in guiding position, said locking means being releasable upon bodily move-` ment -of said element, and resilient means-for -yieldir'igly holding said yguide element in locked position in guiding relation with the drill steel, said resilient means also automatically positively swinging said guide elementabout its .pivot away from the drill steel into .its released non-guiding position whenever said locking -means is released.

Y 14.In a drill steelguide, a support, a pairy of guide arms .mounted on said support for pivotal and bodily movements, means 4for locking said guide arms .in guiding position, said .flocking means being releasable Vupon bodily movement of said-arms relative to saidsupport, and torsion; spring-'means arranged onsaid support and engagi-ngA said guide arms :for vautomatically swinging the latter-apart when saidilockingmeans is released. Y 15. In `a dril-l steel guida-a support having locking means, a pair of` guide arms-mounted on said support for pivotal and' bodily movementsi locking projections onr said arms engageable Ywith iocking means on said-support for holding .said arms against outward swinging movement from steel guiding position, and spring means tending to move said arms bodily relative to said support to vbring said ylocking projections into locking engagementwith said locking lmeana said lock-y ingprojections being releasaloleL from saidlocking means on said support upon bodily movement of said arms relativev to said support 'against the action of said spring means and said arms when unlocked from said support beingfree to swing outwardly from steel guiding position.

' 16. In a drill steel guide, a support, a pair of guide arms, means for mounting said arms on said support for pivotal' and bodily movements, and locking means on said arms and said support for locking said arms individually in guiding position, said locking means being releasable upon bodily movementof said guide armsv in one direction relative to said support.

lZ. In a drill steel guide, a support, a pair of guide arms, means for mounting said arms on said support for pivotal and bodily movements, locking means on said arms and said support for locking said arms individually in 'guiding position, said locking means' being releasable upon bodily movement of said guide arms in one direction relative to said support, 'and means for automatically swinging said guide arms toY wide open position when said locking means is released. "'18. In a drill steel guide a. support, a steel guiding element mounted on said support for movements with respect thereto in different directions in angularly relatedl planes, 'locking means on said support and guiding element for locking the latter against movement in one plane relativeto said support in steel guiding position, said locking. means being releasable upon movement of said guiding element in a diierent plane relative to said support, and means operatively connected to said guiding element and always automatically operative whenever said locking means is released for positively moving said guiding. element in said one plane out of guiding relation with the steel. l 19.@[n` a drill steel guide, a support, a pair of guide arms pivotally mounted on said support. to swing individually relative thereto into and out ofguiding positions, meanson said armsand engageable with said support for locking said arms individually against outward swinging movement from steel guidingy position, and constantly acting means operatively connected to saidarms for always automatically positively swinging said arms either individually orconcurrently outwardly intoV their non-guiding position whenever said lockingmeans is released and for` holding said arms' in said non-guiding position, said locking means when in arm locking position holding saidarms inwardly in guiding assente relation with thej drill steel against the action of said constantly acting means..

20.A centralizar for` drill.- steels comprising asupport, a'fpair of .cooperating guide arms piv.- oted .on parallel. axes .on said support for swingingmovementin transverse planes. with respect thereto, means carried .by said; arms.- and engaging said support for holding .said .guide arms against .outward swinging movement .from steel guiding: position,y .and :means-operatively connectedto. said -arms for. automatically positively swinging said guidelarmsoutwardly into nonguiding position whenever said holding means is released, said arm -holding means holding said arms inwardly. in steel. .guiding position, against the action ot-said. automatic swinging means.

21.- In a drill steel guide, a support, a pair of cooperatingsteel guiding elements mounted on said support. for movement. into and. out of steel guiding position, means onv said support for confining said guiding elements during such movement in transverse planes perpendicular to the longitudinal axis of.V the drill steel, and separate locking devices, oneindividual to each guiding element, for4 separately or. concurrently positively locking said elements in steel guiding position.

, 22. In a drill .steel guide, a support, a pair of cooperating steel guiding elements mounted on said support for. movement into and out of steel guiding position, means on said support for conning said guiding elements during such movement vin transverse planes perpendicular to the longitudinal axis of the drill steelr separate locking devices,v one individualto each guiding element, for separately orconcurrently positively locking 'said elements in steel guiding position, and constantly acting means operable when said locking devices are released to eifect movement of` said guiding elements into their released nonguiding position. f. f

.23. A drill steel guide comprising a support, a guiding element Ymounted on said supportfor lateral movement into and out of guiding relation with a drillsteel and. for translatory movement in a direction longitudinally relative to the drill steel, and locking means on said guiding element and engageable with said support for locking. said guiding element against outward lateral movement from steer guiding position, said locking means being releasable from locking engagement with said support upon translatory movement of said guiding element in one direction and said guiding element when unlocked from said supporti being free to move laterally otutwardly from Vguiding relation with the drill s ee 24'. A drill steel guide comprising a support, a guiding element mounted on said support for lateral movement into and out of guiding relation withl a drill? steel and for translatory movement in a direction longitudinally relative to the drill steel', locking means on said guiding element and engageablewith said support for locking said guiding element in steel guiding position, said locking means being Vreleasable from said support upon translatory movementV of said guiding element Vin one direction, and yieldable means for urging said guiding element translationally toward its `locked guiding position and effective when said locking means is released to move automatically said guiding element laterally out of guiding relation with the drill steel, said guiding elementrb'eing'movable translationally toward its' unlocked position against the action of said yieldable-means.v p

25. A drill steel guide comprising a support, a guiding element pivotally mounted on said support for swinging movement into and out of guiding relation with a drill steel and for translatory. movement in a direction longitudinally relative t0 the drill steel, locking means on said guiding element and engageable with said support for locking said guiding element in guiding position, said locking means being releasable from said support upon translatory movement of said guiding element in one direction, a coiled torsion and compression spring for urging said guiding element translationally toward its locked guiding position and elective when said locking means is released from said support to swing automatically said guiding element out of guiding relation with the drill steel, said guiding element being movable translationally toward unlocked position against the action of said spring.

26. In a rock drill, the combination comprising a guiding support, a drill steel actuator guided on said support for movement toward and from the work, and drill steel guiding means carried by said guiding support and including a guiding element mounted for longitudinal movement in a direction lengthwise of the drill steel and for lateral movement into and out of guiding relation with the drill steel, interlocking means on said support and guiding element for holding said guiding element in steel guiding position and releasable upon longitudinal movement of said guiding element relative to said support, said actuator as it moves forwardly along said guiding support toward the work being operative to effect movement of said guiding element longitudinally relative to said support to effect release of said holding means, and means effective when said holding means is released for moving automatically said guiding element laterally out of guiding relation with the drill steel and into a non-guiding position out of the path of movement of said actuator.

JOHN C. CURTIS. 

